1. Field of the Invention
The present invention relates to a poly(cyclic conjugated diene), and specifically to a poly(cyclic conjugated diene) derived from a specified cyclic conjugated diene monomer, and a process for producing the same; and a paraphenylene polymer and a polymerizing process for the same.
2. Description of the Related Art
Conventionally, various attempts have been made to produce a poly(cyclic conjugated diene) by polymerizing a cyclic conjugated diene monomer, a typical example of which is 1,3-cyclohexadiene. In particular, polymers of cyclic conjugated diene monomers having a high 1,4-position content have been expected as polymers having improved thermal, mechanical and electric properties such as high heat resistance and rigidity, a lowered specific gravity and a lowered dielectric constant, resulting from the linear polymerization thereof.
Japanese Laid-Open Patent Publication No. 7-247321 discloses a polymerizing process of cyclic conjugated diene using a complex compound of an organic compound containing an IA-group metal such as lithium or sodium as an anionic polymerization catalyst. According to this polymerizing process, the cyclic conjugated diene monomer can be polymerized in a high degree by the organic metal compound which forms the complex.
In this process, however, a comonomer for synthesizing a copolymer is restricted to an anionic polymerizable monomer. This is an substantial problem of an anionic polymerizing process.
Japanese Laid-Open Patent Publication No. 6-211916 discloses a polymerizing process of a conjugated diene group using a composite catalyst including a rare-earth metal compound. However, in this process, a sufficient polymer yield cannot be obtained since the rare-earth catalyst has a very high reactivity with a polar compound. Moreover, it is impossible to polymerize a cyclic conjugated diene monomer having a polar functional group. In addition, the usable kind of comonomers may be limited.
As described above, in these processes for producing a cyclic diene polymer, the kind of monomers or comonomers which can be selected is greatly restricted, and polymerization activity is also insufficient.
There is a process of producing polyparaphenylene using a poly(cyclic conjugated diene) as a precursor. The polyparaphenylene has been expected as a conductive polymer material, but is not dissolved in any solvent, and it is not melted even when heated. Thus, polyparaphenylene is difficult to mold. As an effective method for solving the problem, there is a conventional method of polymerizing a cyclohexadiene derivative to obtain a polymer, using the polymer as an soluble precursor to make a film or the like, and then removing substituents from the cyclohexadiene derivative to convert it into polyparaphenylene.
However, the conventional method has the following problem. First, in the polymerization of cyclohexadiene derivatives by radical polymerizing process, the position-selectivity and stereo-selectivity of the molecular structure of the polymer are low. Accordingly, the ratio of the conversion into polyparaphenylene is low so that only a polymer material having a low conductivity can be obtained. Second, in the polymerizing process of a cyclohexadiene derivative using a neutral Ni catalyst, the kind of the polymerizable cyclohexadiene derivatives is limited although the position-selectivity and stereo-selectivity of the molecular structure of the polymer are high. Its activity is also low, and further monomers which can be copolymerized are also restricted.
An object of the present invention is to provide a poly(cyclic conjugated diene) and a polymerizing process for the same; and a phenylene polymer and a process for producing the same, each of which is improved to solve the above-mentioned problems in the related art.
In order to solve the above-mentioned problems, the inventors have eagerly made investigations to succeed in providing a new poly(cyclic conjugated diene) by using a specific catalyst to polymerize a cyclic conjugated diene monomer, and simultaneously succeeded in providing an improved process for polymerizing a cyclic conjugated diene monomer. Thus, the inventors have completed the present invention.
That is, the present invention is a poly(cyclic conjugated diene) comprising: a molecular structure unit having the formula (I) (the molecular structure unit is referred to as a molecular structure unit (A) in this specification) derived from at least one cyclic conjugated monomer, and the unit being bonded to each other at 1,4-position and/or 1,2-position 
wherein n is an integer of 1-6; each X individually represents a carbon, silicon or germanium atom; each R1 individually represents a hydrogen atom or halogen atom, an alkyl, unsaturated hydrocarbon, aryl, cycloalkyl or cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom; at least one of each individual R2 represents an aryl substituted with a hydroxyl group and an alkyl group having 1-4 carbon atoms, iminocarboxyl, alkoxyl, aryloxyl, or alkoxysilyl group, xe2x80x94(CH2)pxe2x80x94OH, xe2x80x94(CH2)pxe2x80x94C(O)xe2x80x94OH, xe2x80x94(CH2)pxe2x80x94C(O)xe2x80x94OR3, xe2x80x94(CH2)pxe2x80x94OR3, xe2x80x94(CH2)pxe2x80x94OC(O)xe2x80x94R3, xe2x80x94(CH2)pxe2x80x94OC(O)xe2x80x94OR3, xe2x80x94(CH2)pxe2x80x94C(O)xe2x80x94R3, xe2x80x94(CH2)pxe2x80x94Oxe2x80x94(CH2)pOH wherein each p is respectively an integer of 0-24, R3 is a linear chain or branched alkyl or aryl group, or a group represented by the following formulae (a)-(h) (in the formulae (a)-(h), Y is a hydrogen atom, an alkyl, alkoxyl, alkoxycarbonyl or cyano group) (these groups of R2are referred to as the polar groups in this specification), or an alkylsilyl, halogenated alkyl, halogenated cycloalkyl, halogenated aryl or halogenated aralkyl group (these groups of R2 are referred to as the non-polar groups); the other R2 represents a hydrogen or halogen atom, a linear chain or branched alkyl, cycloalkyl, alkylidenyl, aryl, aralkyl, alkynyl, vinyl, alkenyl group wherein a supplied alkenyl radical does not contain any terminal double bond, cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom (these groups of R2 are referred to as the substituents); and optionally any two R2s are bonded to each other to form a cyclic structure. 
Further, the present invention is a poly(cyclic conjugated diene) comprising: a molecular structure unit having the formula (II) (the molecular structure unit is referred to as molecular structure unit (B) in this specification) derived from at least one cyclic conjugated diene monomer, and the unit being bonded to each other at 1,4-position and/or 1,2-position: 
wherein n is an integer of 1-6; each X is individual and at least one of them is a silicon or germanium atom; the other X is/are carbon atom(s); each R11 individually represents a hydrogen or halogen atom, an alkyl, unsaturated hydrocarbon, aryl, cycloalkyl or cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom; each R12 individually represents a hydrogen or halogen atom, a linear chain or branched alkyl, cycloalkyl, alkylidenyl, aryl, aralkyl, alkynyl, vinyl, alkenyl group wherein a supplied alkenyl radical does not contain any terminal double bond, cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom (i.e., the substituents); and optionally any two R12s are bonded to each other to form a cyclic structure.
In addition, the present invention is a copolymer comprising two or more kinds of molecular structure units selected from the following 4 kinds of molecular structure units, wherein the molecular structure units (A), (B) and (C) are bonded to a polymer chain at 1,4-position and/or 1,2-position:
one or more kinds of molecular structure unit (molecular structure unit (A)) represented by the formula (I): 
wherein n is an integer of 1-6; each X individually represents a carbon, silicon or germanium atom; each R1 individually represents a hydrogen atom or halogen atom, an alkyl, unsaturated hydrocarbon, aryl, cycloalkyl or cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom; each R2 is individual and at least one of R2s is aryl group substituted with a hydroxyl group and an alkyl group having 1-4 carbon atoms, iminocarboxyl, alkoxyl, aryloxyl, or alkoxysilyl group, xe2x80x94(CH2)pxe2x80x94OH, xe2x80x94(CH2)pxe2x80x94C(O)xe2x80x94OH, xe2x80x94(CH2)pxe2x80x94C(O)xe2x80x94OR3, xe2x80x94(CH2)pxe2x80x94OR3, xe2x80x94(CH2)pxe2x80x94OC(O)xe2x80x94R3, xe2x80x94(CH2)pxe2x80x94OC(O)xe2x80x94OR3, xe2x80x94(CH2)pxe2x80x94C(O)xe2x80x94R3, xe2x80x94(CH2)pxe2x80x94Oxe2x80x94(CH2)pOH wherein each p is respectively an integer of 0-24, R3 is a linear chain or branched alkyl or aryl group, or a group represented by the following formulae (a)-(h) (in the formulae (a)-(h), Y is a hydrogen atom, an alkyl, alkoxyl, alkoxycarbonyl or cyano group) (these groups of R2 are referred to as the polar groups in this specification), or an alkylsilyl, halogenated alkyl, halogenated cycloalkyl, halogenated aryl or halogenated aralkyl group (these groups of R2 are referred to as the non-polar groups); the other R2represents a hydrogen or halogen atom, a linear chain or branched alkyl, cycloalkyl, alkylidenyl, aryl, aralkyl, alkynyl, vinyl, alkenyl group wherein a supplied alkenyl radical does not contain any terminal double bond, cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom (these groups of R2 are referred to as the substituents); and optionally any two R2s are bonded to each other to form a cyclic structure, 
one or more kinds of molecular structure unit (molecular structure unit (B)) represented by the formula (II): 
wherein n is an integer of 1-6; each X is individual and at least one of them is a silicon or germanium atom; the other X is/are carbon atom(s); each R11 individually represents a hydrogen or halogen atom, an alkyl, unsaturated hydrocarbon, aryl, cycloalkyl or cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom; each R12 individually represents a hydrogen or halogen atom, a linear chain or branched alkyl, substituted or non-substituted cycloalkyl, alkylidenyl, aryl, aralkyl, alkynyl, vinyl, alkenyl group wherein a supplied alkenyl radical does not contain any terminal double bond, cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom; and optionally any two R12 s are bonded to each other to form a cyclic structure,
one or more kinds of molecular structure unit represented by the following formula (III) (the molecular structure unit may be referred to as molecular structure unit (C)): 
wherein n is an integer of 1-6; each R21 individually represents a hydrogen or halogen atom, an alkyl, unsaturated hydrocarbon, aryl, cycloalkyl or cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom; each R22 individually represents a hydrogen or halogen atom, a linear chain or branched alkyl, substituted or non-substituted cycloalkyl, alkylidenyl, aryl, aralkyl, alkynyl, vinyl, alkenyl group wherein a supplied alkenyl radical does not contain any terminal double bond, cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom; and optionally any two R22s are bonded to each other to form a cyclic structure,
one or more kinds of molecular structure units derived from one or more kinds of monomers selected from monomers containing a double bond (the molecular structure unit is referred to as molecular structure unit (D)).
Additionally, the present invention is a poly(cyclic conjugated diene) wherein molecular structure unit (the molecular structure unit is referred to as the molecular structure unit (C)) is represented by the following formula (III) and the molecular structure unit is bonded to each other at 1,4-position and/or 1,2-position: 
wherein n, X, R21 and R22 have the same meanings as defined in the formula (IIIA),
the polymer being obtained by using a compound represented by the following (IV) (which may be referred to as the present mono-component catalyst):
[Scheme 51]
[LnMXm]a+[A]axe2x88x92xe2x80x83xe2x80x83(IV) 
wherein M represents a transition metal element of the eighth, ninth or tenth group in the periodic table; L represents a ligand having 1-3 xcfx80 bonds; X represents a ligand having at least one "sgr" bond and 0-3xcfx80 bonds; n is 0,1 or 2; m is 0 or 1; both of n and m are not 0 at the same time; when m is 0, a is 2; when m is 1, a is 1; and A represents a counter anion of [LnMXm]a+,
so as to polymerize one or more kinds of cyclic conjugated diene monomers represented by the following formula (IIIA) (the monomer(s) may be referred to as monomer(s) (C)): 
wherein n is an integer of 1-6; each R21 individually represents a hydrogen or halogen atom, an alkyl, unsaturated hydrocarbon, aryl, cycloalkyl or cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom; each R22 individually represents a hydrogen or halogen atom, a linear chain or branched alkyl, substituted or non-substituted cycloalkyl, alkylidenyl, aryl, aralkyl, alkynyl, vinyl, alkenyl group wherein a supplied alkenyl radical does not contain any terminal double bond, cyclodienyl group, or a 5-10-membered heterocyclic group having at least one of nitrogen, oxygen and sulfur atoms as a heteroatom; and optionally any two R22s are bonded to each other to form a cyclic structure.
Besides, the present invention is a process for producing a poly(cyclic conjugated diene) comprising the step of polymerizing a cyclic conjugated diene monomer or a cyclic conjugated diene monomer and a double bond-containing monomer by using a compound represented by the following formula (IV) (which is referred to as the present mono-component catalyst in this specification):
[Scheme 53]
[LnMXm]a+[A]axe2x88x92xe2x80x83xe2x80x83(IV) 
wherein M represents a transition metal element of the eighth, ninth or tenth group in the periodic table; L represents a ligand having 1-3xcfx80 bonds; X represents a ligand having at least one "sgr" bond and 0-3xcfx80 bonds; n is 0,1 or 2; m is 0 or 1; both of n and m are not 0 at the same time; when m is 0, a is 2; when m is 1, a is 1; and A represents a counter anion of [LnMXm]a+, or
a multi-component catalyst containing:
(a) a transition metal compound of a transition metal element of the eighth, ninth or tenth group in the periodic table, and
(b) an organic aluminum compound, and/or
(c) an electron donating component (the multi-component catalyst may be referred to as the present multi-component catalyst in this specification).
The present invention has the following advantages.
(1) It is possible to provide a new poly(cyclic conjugated diene) and a process for producing the same.
(2) It is possible to provide a modifying product or a hydrogenated product of a poly(cyclic conjugated diene) having high heat resistance and oxidation resistance, and a hydrogenating process for them by adding hydrogen to the poly(cyclic conjugated diene).
(3) It is possible to obtain a poly(cyclic conjugated diene) at a high yield by conducting polymerizing reaction of a cyclic conjugated diene monomer in the presence of a base compound.
(4) It is possible to obtain a poly(cyclic conjugated diene) at a high yield by conducting polymerizing reaction of a cyclic conjugated diene monomer in an aromatic halide.
(5) It is possible to obtain a poly(cyclic conjugated diene) having a high crystallizability by conducting polymerizing reaction of a cyclic conjugated diene monomer in the presence of a Ni-based catalyst.
(6) It is possible to obtain a phenylene polymer at a high yield by conducting polymerizing reaction of a cyclohexadiene derivative in the presence of a Ni-based catalyst.